Nitrous oxide pollution levels in oral surgery offices.

: Nitrous oxide pollutant levels, surveyed in oral surgery offices in Southern California, were lower than previously reported. These evaluations were related to rebreathed gas samples obtained from the operator and assistants, and appear to correlate well with exposure to nitrous oxide contamination. The lower levels in the hallway were tenfold less than those previously reported. Better air-conditioning in these offices and better airway control could be responsible, in part, for the difference.